TIDT324 February   2023

 

  1.   Description
  2.   Features
  3.   Applications
  4. 1Test Prerequisites
    1. 1.1 Voltage and Current Requirements
    2. 1.2 Required Equipment
    3. 1.3 Considerations
  5. 2Testing and Results
    1. 2.1 Efficiency Graphs
    2. 2.2 Efficiency Data
    3. 2.3 Thermal Images
    4. 2.4 Dimensions
  6. 3Waveforms
    1. 3.1 Switching
    2. 3.2 Output Voltage Ripple
    3. 3.3 Load Transient
    4. 3.4 Start-Up

3.4 Start-Up

#FIG_Z3J_FHK_2MB to #FIG_CVJ_JNM_JWB show the output voltage start-up waveforms at 12-V input and –8-V output with the converter starting up into no load and into 2.7-A constant-current load using the electronic load. Two methods of enabling the converter were exercised and captured: one where the input voltage is already turned ON and the converter waits for the enable signal to go HIGH; the other where the enable signal is tied to VIN and the converter waits for the main power supply to be turned ON.

GUID-20230202-SS0I-6HMH-XMC8-QPBCQBNHBQL2-low.png Figure 3-8 Start-Up Into No Load, 12-V Input, –8-V Output, Start-Up Initiated via the Enable Connection (input Supply Already Turned ON)
GUID-20230202-SS0I-HCRF-CJL3-C6PF3ZS6FDHX-low.png Figure 3-9 Start-Up Into 2.7-A Constant-Current Load, 12-V Input, –8-V Output Start-Up Initiated via the Enable Connection (input Supply Already Turned ON)
GUID-20230202-SS0I-PCQS-7FSX-HVV3SPHH8PW3-low.png Figure 3-10 Start-Up Into No Load, 12-V Input, –8-V Output, Start-Up Initiated via Input Supply (Enable Signal Already Set HIGH)
GUID-20230202-SS0I-HT6G-BSKC-NCVBNMB9CJNB-low.png Figure 3-11 Start-Up Into 2.7-A Constant-Current Load, 12-V Input, –8-V Output, Start-Up Initiated via Input Supply (Enable Signal Already Set HIGH)